Macbook 2016 stuck in an update loop

I just experienced this problem on my TbMbp. When you boot into normal mode, it will present you the Network Connection screen to choose a WiFi access point or Ethernet. No matter what you do, it will always fail and leave you with the message where the Mac can't start up unless the critical update is installed. This was performed on a 2016 model 15 inch MBP (flagship model).

Here's what I tried:

- SMC and NVRAM reset
- Online Recovery, First Aid on internal SSD
- Mac Diagnostic Utility (showed no problems)
- Time Machine Backup from an earlier, working point in my backup history
- Delete Partition, reload OS from scratch via Internet Recovery

None of these worked. It will always present you with the description at the top of this posting.

Symptoms:

- Will boot into Safe Boot fine. (This is how I managed to save my files to an external HDD)
- Touchbar will not light up, no way to control brightness, volume, etc. from the touchbar.

What I found on the internet about this problem:

- The Mac's OS and the Touchbar's OS (two separate OS's) are having a problem recognizing each other. The T1 CPU for the Touchbar cannot start up because the Macbook's OS (OS X High Sierra) is unable to "see" the Touchbar.

Solution:

- After chatting with Apple online and trying a few things listed above, I asked to schedule my laptop for service at the nearest Apple Store Genius Bar.

- At the Genius Bar, the tech has never heard of this problem at his location, and connected my TbMbp (Touch bar Macbook Pro) to their in-house diagnostic server, and ran something called "Mac Resource Inspector" (MRI) from an iPad. MRI is some kind of Apple Tech-only diagnostic software which connects to a machine inside the store.

- After 15 minutes, I noticed the Touchbar light up, I could see some of the Touchbar controls show up. The diagnostics did not complete until 5 minutes later where it said it found no problems.

- The tech then restarted my machine but each time performed a NVRAM reset before allowing my computer to continue booting into Normal Mode. I noticed my Touchbar light up before finally showing me the login screen.

Final Thoughts:

- I read that some people had their machines shipped out for servicing or replacement. I can't be sure if the problem I experienced is the exact same thing as everyone else but it appears that the MRI software was able to either reset something or actually loaded something into my machine allowing the problem to go away.

- I would strongly suggest that you schedule an appointment and have the Apple Genius Bar technician run the MRI software on your machine.

I hope this helps.

Just ran into this "critical software loop" today when updating my 2017 MacBook Pro 15 with touch bar to MacOS High Sierra. And I finally made my mac out of the loop.

Here is the frustrating part:

At the end of updating process, this critical software loop showed up, try again was never helping. So I made an internet install (when restarting mac, press Option-Command-R, and choose reinstall MacOS on existing disk, thank god I didn't format it), when the reinstall process reach the end, this “critical software loop” showed again…

Here is where magic(or luck) happens:

During the whole updating/reinstall process, I had a third party USB-C hub (it also deliver power to my macbook)and logictech mouse signal transmitter (connecting via a USB-C to normal USB connecter) attached to my macbook’s two thunderbolt 3 ports.
At the last time this “Critical software loop” showed up,
I removed these two peripherals (now the macbook is on battery only), and I see the screen went black, and I then plugged the original power cable to my mac, and the install progress bar showed again, and boom! the login page showed up!

This might be single case, but worth a shot.
Just play around with the power cable (unplug it and later plug it).

I had this same problem. I tried reinstalling the OS by hitting command + r, but ran into the same prompt and error message upon startup all over again. I made sure my computer was connected to an adapter and just kept hitting "try again" over and over again until it worked. Better get something to do during this process as it takes a good 2 minutes between error messages and it took me about 5-10 tries before the "critical update" finally installed.

Just experienced the same thing on MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports).

I inadvertently let the battery drain to 0% which seemingly triggered the update loop.

Resetting the SMC solved the problem.

In my case the problem was caused by a Hama USB3 hub. Every time I booted with the hub plugged in any of the USB-C ports, the "Critical update" recovery window showed. Resetting SMC also worked, though it was quite unnecessary. I even reinstalled a fresh macOS High Sierra before I came to the conclusion that the hub was causing the problem and now I feel stupid.

Hope this helps.

I believe that I have resolved the issue through the simple process below:

1. As I use my mobile phone to access the internet, I simply connected my mobile to the MacBook via a cable.

2. I accessed the App Store/Update via the apple menu on finder

3. Selected the critical update and asked it to install.

Seeing as it no longer asked me for a wifi network and simply accessed the internet as required during the update process, it finally managed to install the update and I no longer see it in the App Store. It has only been a couple of days, but to date there have been no issues and because it is no longer an update in the App Store, I don't believe it will be.

Hope this helps.

Mike

SOLUTION:

https://discussions.apple.com/thread/8106654?start=0&tstart=0

A tried a billion suggestions, but this one worked. Get a book, hit the button to “try again” i hit it five to eight times, and suddenly the touchbar lit up, and then a black screen with an Apple and below it a sentence like,... update continuing to load,... the bar advanced, finished, screen went black and the it pop to life, touch bar lit and the issue resolve.

So,...I then decided to update all Securities updates and **** if it didn’t do the same thing, but I decided to just push the “try again“ another five times around, and again, same thing, it finally loaded the update. Personally I think this is a software/hardware issue. Apple hasn’t figured out their code implication with the touchbar integration and so they write updates that get looped.

As of November 2017, if you still have the error, boot into safe mode by holding shift. Then go enrol your mac in the public beta and download the latest software update from the Appstore. For me it's 10.13.2. Let the process complete. The touchbar will reappear and the boot will complete successfully.

Great suggestion. If the Wi-Fi is turned off, just press the Wi-Fi icon in the upper right corner and reconnect to your Wi-Fi. The choose the re-install the OS. Wait until the macbook re-downloads the OS and then go throigh the re-booting process.

I SOLVED it with a SMC reset ( MacBook Pro 15" 2016 with touchbar)

1- TURN OFF MAC, REMOVE USB-C POWER SUPPLY CABLE AND ANY PERIPHERAL

2- WAIT 10 SECONDS

3- PRESS SHIFT + CONTROL + OPTION + POWER FOR 10 SECONDS

4- WAIT 5 SECONDS

5- CONNECT USB-C POWER SUPPLY

6- POWER ON.

A small apple logo should appear in the center of the screen and a dashed progress bar at the bottom of the screen: Don't worry the machine is booting normally.

Enter your password and you are ready to go!

Reboot to ensure everything works correctly on next boot.

In addition to the Update loop, "fortunately" my batteries also got totally drained and macbook did not charge anymore.

If my batteries were not got drained I would have reinstalled the OS, but that is not the right solution apparently.

Apple Care helped me to but there is not clear procedure for update loop, luckily my batteries drained triggered the idea to me and the apple agent to give it a try with the SMC Reset.

Finally it seems there is no such Critical Update pending, is just an error produced by some SMC / MacOS combined disruption.

To clarify point 1.

I used the personal hotspot feature on my iPhone and connected to the internet via the usb cable, not via wifi.

I would be interested to know whether anyone who hardwires their internet connection has had this problem.

In trying to set up and log into my new Macbook Pro 15" with TouchBar, I got only as far as entering my network information when I received the error message:

A critical software update is required for your Mac, but an error was encountered while installing this update. Your mac can't be used until this update is installed.

On the advice of others posting here, I did a re-install of the OS from Command-R. This did not help me. I tried several times.

Then (also from within Command-R) I erased and re-formatted the hard drive, re-installed the OS, and for the first time was able to get as far as inputting my time zone and setting up a user account.

The first thing I did once I finally gained access to my new computer was to visit the App Store and download updates. One of the App Store system updates needed a re-start.

When the computer re-started, it made it to the log-in screen. However, after I entered my password, the screen froze, with a spinning beach ball. I was not able to login again to the account.

I did a hard re-start. When the system started again, I was prompted for my WIFI network, and then received the same error message:

A critical software update is required for your Mac, but an error was encountered while installing this update. Your mac can't be used until this update is installed.

Help??!

Had this exact problem.

Was finally solved by booting in safe mode (with shift) and creating a new network location that did not use our corporate proxy server.

After this i rebooted normally, selected my iPhone as wifi network. This time it was able to complete install the critical software update. So it seems that it for some reason cant connect through a proxy when it does the final setup of the update.

This fixed it for me! I was worried for a moment. You are a legend @diegoCAS.